Speaker Problem

I bought a speaker today and you can plug it up with a dual jack cord or you can use bluetooth. The speaker that I purchased also came with a remote. When I tried to skip songs songs using bluetooth it worked perfectly. But when I try to change it with the jack plugged in, it won't change. The only thing that will work is the volume on the speaker. The speaker is a Craig portable bluetooth sound system with rechargeable lithium ion battery, model #: CR4189BT